The present invention relates to a heat exchanger of the general type having a plurality of individual tubular parts connected with one another wherein the tubular parts are inserted into each other and are plastically deformed to obtain a press fit. The invention also pertains to a process for the manufacture of such a heat exchanger.
A method for joining tubular parts with the aid of an intermediate piece and for connection of a tubular part with a housing wall is known from British Pat. No. 720,553. The tubular parts have at their ends a flange, resting in a stepped bore of the intermediate piece or of the housing wall. A pressure ring surrounding the tubular part is pressed into the expanded part of the stepped bore. This results in a press fit between the housing or the intermediate piece and the pressure ring, which holds the flange against the stepped shoulder of the bore.
The joining of tubular parts in this manner is not suitable for mass production, because the use of intermediate pieces and the production of the tube flanges result in high costs. Furthermore, the pressing in of each individual pressure ring is highly labor-intensive and again leads to high costs. Application in heat exchangers with several rows of tubes is not possible because the tube connections of the inner rows of tubes are not accessible. The known tube joint therefore cannot be considered for heat exchangers.